Question

If a car has a constant acceleration of 4m/s,starting from rest,how far has it travelled by the time it reaches the speed of 40m/s

Answer 1

Answer:

200 meters.

Explanation:

Given,

a=4m/s² ; u(initial velocity)=0(because it is stating from rest).

speed(v)= 40m/s

a=v-u/t  [Formula]

4  =40-0/t

t=10seconds.

S=ut+1/2 at² [Formula]

S= 0 x 10+ 1/2 x 4 x 10 x 10

S= 0+ 2 x 10 x10

S= 200 meters.

Hope it helps:)

Answer 2

Answer:

400 m

Explanation:

First Lets Calculate Time:-

$acceleration(a) = 4{m.sec}^{2} \\ initial \: velocity(u) = 0 \: m. {sec}^{ - 1} \\ final \: velocity(v) = 40m. {sec}^{ - 1} \\ time(t) = {?} \\ = )a \: = \frac{v - u}{t} \\ = ) \frac{40 - 0}{t} = 4 \\ = )40 = 4t \\ = )t = 10 \: sec$

So time is 10 sec

Lets Use Second Equation Of Motion

s = ut +( 1/2 x at²)

=)(0 x 10) + (1/2 x 4 x 10 x 10)

=)0 + (1/2 x 400)

=)0 + 200

=)200 m

Hope it helped